CN115972769B - Plasma-based crosstalk-prevention arrayed electrofluidic jet printing device and method - Google Patents

Abstract

The present invention discloses a plasma-based anti-crosstalk arrayed electro-fluid printing device and method, belonging to the field of inkjet printing technology. The printing device includes an arrayed printing head and an arrayed plasma module. The arrayed printing head is composed of a plurality of ink supply nozzles to form a nozzle group, and the upper end of the ink supply nozzle is connected to the ink supply unit; the arrayed plasma module generates plasma and forms a plasma gaseous annular electrode; the substrate to be printed is grounded, and an electric field is formed between the plasma gaseous annular electrode, and the electric field guides the ink supply nozzle to generate Taylor cone injection, so that high-resolution ink is deposited on the substrate. The gaseous annular electrode composed of plasma can be controlled by the discharge gas or voltage of the plasma, respectively, and no crosstalk will occur between the arrayed gaseous annular electrodes, and the electro-fluid printing nozzles can be independently controlled; it can provide new technical support in the high-precision, high-resolution, and high-efficiency manufacturing of large-area display panel pixel arrays, sensor arrays, etc.

Description

A plasma-based anti-crosstalk arrayed electrofluid printing device and method

Technical Field

The present invention belongs to the technical field of inkjet printing, and more specifically, relates to a plasma-based anti-crosstalk arrayed electro-fluid printing device and method.

Background Art

As an additive manufacturing technology, inkjet printing technology has the advantages of non-contact, large area, no need for mask, rapid manufacturing, low-cost finished products, and direct pattern manufacturing on flat/curved substrates. It is the main manufacturing technology for printed electronics that will replace the long process of photolithography/vacuum (development, etching, exposure and cleaning, etc.), and is widely used in display, sensing, chip, energy, aerospace and other fields. Traditional inkjet printing technology has the disadvantages of low resolution, easy nozzle clogging, and limited printing materials and droplet size. Electrofluidic printing technology is an emerging inkjet printing technology. It can realize micro-nano-sized ink droplets/jets by "pulling" Taylor cone jets at the ink nozzle through structured electric field driving, and is compatible with ink materials with a viscosity range of 1-10000cp. On the basis of continuing the advantages of traditional inkjet printing technology, it also has many unique advantages such as high resolution, multiple printing modes, and a wider range of material applications. It has outstanding potential in the high-precision manufacturing of large-area micro-nano structures.

For electrofluidic printing, arraying inkjet heads can effectively improve the efficiency of electrofluidic printing and achieve high-resolution and high-efficiency preparation of large-area printed electronic devices, which is of great significance. At present, the research on arrayed electrofluidic printing is not in-depth enough and there are many problems. For example: (1) The electric field of arrayed electrofluidic printing crosstalks with each other. Arrayed printing heads need to apply high-voltage electric fields between different nozzles, and there is a serious electric field crosstalk phenomenon. The jets at each nozzle will appear uneven and tilted, and cannot cope with high-precision printing occasions; (2) Arrayed electrofluidic printing has poor independent controllability. Depending on the nature of the inkjet, the operating voltage of electrofluidic printing can reach several thousand volts, which is difficult to achieve high-frequency and multi-channel independent control requirements; (3) The design and manufacture of high-precision and high-density nozzle arrays are complex. Arrayed electrofluidic nozzles need to prepare a large number of nozzle structures with high aspect ratios. The packaging volume and integration level of their internal components need to be considered, and the preparation process is difficult. Therefore, it is urgent to propose a new arrayed electrofluidic printing device and method to solve the problem that the arrayed electrofluidic printing heads are all connected to high-voltage electrodes and crosstalk with each other during linkage control or independent control, which affects printing, and improve the consistency and controllability of printing.

Summary of the invention

In view of the defects of the prior art and the need for improvement, the present invention provides a plasma-based anti-crosstalk arrayed electrofluidic printing device and method. The arrayed electrofluidic printing device can use the plasma gaseous annular electrode to guide the inkjet nozzle to generate Taylor cone jets by setting an arrayed printing head and an arrayed plasma gaseous annular electrode, so that the ink is accurately deposited on the substrate. The annular electrodes composed of plasma can be controlled by the discharge gas or voltage of the plasma, respectively, and no crosstalk will occur between the arrayed electrodes. In addition, the arrayed electrofluidic printing head improves the printing efficiency of electrofluidic inkjet printing, thereby enabling high-precision, high-resolution, and high-efficiency electrofluidic inkjet printing on large-area display panels, sensor arrays, and other surfaces.

To achieve the above-mentioned object, in a first aspect, the present invention provides a plasma-based anti-crosstalk arrayed electro-fluid printing device, comprising: an arrayed printing head and an arrayed plasma module;

The arrayed print head comprises a plurality of ink supply nozzles, the upper end of each ink supply nozzle is connected to an ink supply unit, and ink flows out from the ink supply unit to fill the ink supply nozzle;

The arrayed plasma module includes a gas supply unit, a high voltage power supply and a plurality of plasma units, each of which includes a plasma generating device and a plasma delivery hose;

The gas supply unit is connected to each plasma generating device through a flow meter to individually control the delivery of the working gas in each plasma unit; the high-voltage power supply is connected to the electrode needle in each plasma generating device through an electrical switch to individually control each plasma generating device to generate plasma;

One end of the plasma delivery hose is connected to the plasma generating device, and the other end surrounds the lower end of the ink supply nozzle to form a plasma gas ring electrode; wherein, the plasma gas ring electrode is used to form an electric field with the grounded substrate to be printed, so that when the electric field strength on the surface of the ink curved liquid surface exceeds the Taylor limit, the ink generates a Taylor cone spray and is deposited at a designated position on the substrate to be printed.

Furthermore, when the substrate to be printed is a conductive substrate, the conductive substrate is grounded; when the substrate to be printed is an insulating thin substrate, a conductive pad needs to be placed under the insulating thin substrate and the conductive pad is grounded.

Furthermore, the working gas is argon, helium, nitrogen or air.

Furthermore, the high voltage power supply is a pulse power supply or a radio frequency power supply.

To achieve the above objectives, in a second aspect, the present invention provides a plasma-based anti-crosstalk arrayed electrofluid printing method, wherein the printing method is performed using the plasma-based anti-crosstalk arrayed electrofluid printing device described in the first aspect.

Furthermore, the printing method comprises the following steps:

S1, vertically placing the arrayed printing head above the substrate to be printed, winding each plasma delivery hose around the lower end of the corresponding ink supply nozzle, and delivering ink to each ink supply nozzle through the ink supply unit, and the ink fills the ink supply nozzle and reaches the outlet at the lower end of the ink supply nozzle;

S2, supplying working gas to the plasma unit that needs to work, and turning on the corresponding electrical switch, so that the high-voltage power supply transmits voltage to the electrode needle of the plasma generating device, and the working gas discharges at the electrode needle to generate plasma;

S3. The generated plasma flows along the plasma delivery hose under the blowing of the airflow, and a plasma gaseous ring electrode is formed around the lower end of the nozzle, thereby forming an electric field between the grounded substrate to be printed. When the electric field strength on the surface of the ink curved liquid surface exceeds the Taylor limit, the ink is ejected in a Taylor cone and deposited at a specified position on the substrate to be printed, thereby completing arrayed electrofluid printing.

Furthermore, when the flow meter controls the working gas to stop supplying, or the electrical switch controls the electrode needle to be disconnected from the high-voltage power supply, the plasma generating device stops generating plasma, and thereby the ink supply nozzle stops spraying ink and printing stops, thereby realizing independent control of each ink supply nozzle.

In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

(1) The present invention combines plasma with inkjet printing, and uses the positive charge carried by the plasma itself to form an electric field between the plasma gaseous annular electrode area and the substrate to be printed, thereby guiding the ink supply nozzle to generate electrohydrodynamic force to eject ink and accurately deposit it at the specified position of the substrate to be printed. This can overcome the problem of low printing accuracy of inkjet printing on the substrate, effectively improve the accuracy, resolution and convenience of inkjet printing, and can be well compatible with typical printing modes such as continuous direct writing, on-demand printing and near-field spinning, and realize high-precision and high-resolution inkjet printing;

(2) The inkjet nozzles of the present invention are arrayed and can be used for high-resolution printing on large-area structural parts. They are of great significance for improving the printing efficiency of electrofluidic printing and realizing high-resolution and efficient preparation of printed electronic devices. The electrical switch can control the connection and disconnection of the high-voltage power supply and the electrode needle, and the flow meter can control the supply of the working gas. Both methods can stop the inkjet nozzle from printing, and can realize independent control of each inkjet nozzle in the arrayed electrofluidic printing nozzle group.

(3) The arrayed inkjet printing heads of the present invention all use positively charged plasma as electrodes, that is, the plasma jet develops along the plasma delivery hose under the blowing of the airflow, and the plasma delivery hose surrounds the lower end of the ink supply nozzle to form a plasma gas ring electrode of the inkjet head. The electric fields generated by the plasma gas ring electrodes will not affect each other, thus overcoming the problem that in traditional electro-fluid inkjet printing, the arrayed inkjet printing heads are all connected to high-voltage electrodes, which cause crosstalk and affect printing when they are independently controlled or linked and controlled simultaneously, thereby improving the consistency and controllability of printing.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic structural diagram of a plasma-based anti-crosstalk arrayed electro-fluid printing device constructed according to a preferred embodiment of the present invention with a conductive substrate as a substrate to be printed;

2 is a schematic structural diagram of a plasma-based anti-crosstalk arrayed electro-fluid printing device constructed according to a preferred embodiment of the present invention with an insulating substrate as a substrate to be printed;

FIG. 3 is a diagram showing the printing results of the device constructed according to the preferred embodiment of the present invention.

Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

1-high voltage power supply; 2-gas supply unit; 3-flow meter; 4-electrode needle; 5-plasma; 6-plasma gaseous ring electrode; 7-ink deposition; 8-electrical switch; 9-plasma generator; 10-plasma delivery hose; 11-ink supply nozzle; 12-ink; 13-conductive substrate; 14-insulating substrate; 15-conductive pad.

DETAILED DESCRIPTION

In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Please refer to FIG. 1 and FIG. 2 , the present invention provides a plasma-based anti-crosstalk arrayed electrofluid printing device, comprising: an arrayed printing head and an arrayed plasma module, wherein:

The arrayed print head is composed of a plurality of ink supply nozzles 11 forming a nozzle group. When in operation, the upper end of the ink supply nozzle 11 is connected to the ink supply unit, and the ink 12 flows out from the ink supply unit. The ink 12 flows along the channel inside the ink supply nozzle 11 to the outlet at the lower end of the ink supply nozzle 11.

The arrayed plasma module includes a gas supply unit 2, a high-voltage power supply 1 and a plurality of plasma units, each of which includes a plasma generator 9 and a plasma delivery hose 10; the gas supply unit 2 can individually control the delivery of the working gas in each plasma unit through a flow meter 3, and the working gas can be argon, helium, nitrogen or air; the high-voltage power supply 1 can be a pulse power supply or a radio frequency power supply, and an electrode needle 4 is arranged inside the plasma generator 9, and an electrical switch 8 can uniformly control the connection and disconnection of each electrode needle 4 with the high-voltage power supply 1. When the gas supply unit 2 supplies gas to the plasma unit that needs to work, the working gas reaches the plasma generator 9 along the gas pipe, the high-voltage power supply 1 is turned on, and the voltage reaches the electrode needle 4 through the control of the electrical switch 8, and the working gas discharges at the electrode needle 4 to generate plasma 5, and the plasma 5 flows along the plasma delivery hose 10 under the blowing of the air flow, and the plasma delivery hose 10 surrounds the lower end of the ink supply nozzle 11 to form a plasma gaseous annular electrode 6.

The substrate to be printed can be a conductive substrate 13 (as shown in FIG1 ) or an insulating substrate 14 (as shown in FIG2 ). When the substrate to be printed is the conductive substrate 13, it is only necessary to ground the conductive substrate 13; when the substrate to be printed is the insulating substrate 14, it is necessary to place a conductive pad 15 under the insulating substrate 14 and ground the conductive pad 15, and the thickness of the insulating substrate 14 should not be too large.

During operation, a strong electric field is formed between the substrate to be printed and the plasma gaseous annular electrode 6. When the electric field strength on the surface of the curved liquid surface of the ink 12 exceeds the Taylor limit, the ink 12 is ejected in a Taylor cone, and the ink 12 is deposited at a designated position on the substrate to be printed to form an ink deposit 7, thereby completing printing.

Furthermore, the electrical switch 8 controls the connection and disconnection between the electrode needle 4 and the high-voltage power supply 1, and the working gas stops discharging, or the flow meter 8 controls the working gas to stop supplying. Both of these methods will stop the generation of the plasma 5, thereby stopping the ink 12 inside the ink supply nozzle 11 from spraying out and printing from stopping, thereby realizing independent control of each of the ink supply nozzles 11 in the arrayed electro-fluid printing head group.

Furthermore, the arrayed printing heads all use the plasma 5 as the gaseous electrode, thus avoiding the problem that the arrayed printing heads in the traditional electrofluid printing are all connected to the high-voltage electrode and the crosstalk affects the printing when they are independently controlled or linked and controlled simultaneously. That is, when there are two adjacent arrayed units, the plasma generating device 9 of the arrayed unit on the left is fed with the working gas and the electrode needle 4 is connected to the high-voltage power supply 1, the plasma 5 is generated to form a plasma gaseous annular electrode 6, thereby generating an electric field to guide the ink supply nozzle 11 on the left to generate Taylor cone injection for printing; while the plasma generating device 9 of the arrayed unit on the right is not fed with the working gas or the electrode needle 4 is not connected to the high-voltage power supply 1, and there is no plasma 5 in the plasma delivery hose 10 to form a plasma gaseous annular electrode 6, so that no printing is performed. The electric field generated by the plasma 5 in the plasma gaseous annular electrode 6 of the left arrayed unit will not affect the electrode area of the right arrayed unit, that is, the right arrayed unit still does not generate an electric field and remains in a state of stopping printing. In the arrayed electrofluid printing device, the start and stop of the working state of each arrayed unit and the distance between the inkjet nozzles will not affect the working state of other arrayed units, thereby improving the controllability of arrayed electrofluid printing.

According to another aspect of the present invention, as shown in FIG. 1 and FIG. 2 , a plasma-based anti-crosstalk array electrofluid printing method is proposed, the method comprising the following steps:

S1. Place an arrayed printing head composed of a plurality of ink supply nozzles 11 vertically above the substrate to be printed. The substrate to be printed may be a conductive substrate 13 as shown in FIG. 1 or an insulating substrate 14 as shown in FIG. 2. When the substrate to be printed adopts the conductive substrate 13, the conductive substrate 13 should be grounded; when the substrate to be printed adopts the insulating substrate 14, a grounded conductive pad 15 should be placed underneath. Wrap the plasma delivery hose 10 around the lower end of the ink supply nozzle 11, and deliver ink 12 to the outlet of the ink supply nozzle 11 through the ink supply unit to each ink supply nozzle 11;

S2, the gas supply unit 2 delivers the working gas to the plasma generator 9 to be used through the flow meter 3. The working gas can be argon, helium, nitrogen or air. The plasma generator 9 is provided with an electrode needle 4, which is connected to a high-voltage power supply 1 through an electrical switch 8. The high-voltage power supply 1 can be a pulse power supply or a radio frequency power supply. When the high-voltage power supply 1 is turned on, the voltage reaches the electrode needle 4, and the working gas discharges at the electrode needle 4 to generate plasma 5;

S3, the plasma 5 flows along the plasma delivery hose 10 under the blowing of the airflow, and the plasma delivery hose 10 surrounds the lower end of the ink supply nozzle 11 to form the plasma gaseous annular electrode 10, thereby forming an electric field with the grounded substrate to be printed, and the electric field induces the ink supply nozzle 11 to generate a Taylor cone jet, thereby driving the ink 12 to be ejected and deposited. When the electric field intensity on the curved liquid surface of the ink 12 exceeds the Taylor limit, the ink 12 generates a Taylor cone jet and is deposited at a designated position on the substrate to be printed to form an ink deposit 7, thereby completing arrayed electrofluidic printing.

Furthermore, the electrical switch 8 controls the connection and disconnection between the electrode needle 4 and the high-voltage power supply 1, and the working gas stops discharging, or the flow meter 8 controls the working gas to stop supplying. Both of these methods will stop the generation of the plasma 5, thereby stopping the ink 12 inside the ink supply nozzle 11 from spraying out and printing from stopping, thereby realizing independent control of each of the ink supply nozzles 11 in the arrayed electro-fluid printing head group.

FIG. 3 is a diagram showing the arrayed printing results of the device constructed according to the preferred embodiment of the present invention.

The present invention combines plasma with inkjet printing, and uses the positive charge carried by the plasma itself to form an electric field, thereby guiding the inkjet nozzle to generate electrofluidic jet to print out ink and accurately deposit it on a specific position of the substrate to be printed, effectively improving the accuracy, resolution and convenience of inkjet printing. The arrayed design can be used for high-resolution printing on the surface of large-area structural parts, which is of great significance for improving the printing efficiency of electrofluidic jet printing and realizing high-resolution and efficient preparation of printed electronic devices. In addition, independent control of each inkjet nozzle in the arrayed electrofluidic jet printing nozzle group can be achieved through an electrical switch and a flow meter. With a positively charged plasma as an electrode, the electric fields generated by each plasma gaseous annular electrode will not affect each other, overcoming the problem that the arrayed jet printing heads in traditional electrofluidic jet printing are all connected to high-voltage electrodes and crosstalk with each other when they are independently controlled or linked and controlled at the same time, affecting the printing, and improving the consistency and controllability of printing.

It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A plasma-based cross-talk prevention arrayed electrofluidic inkjet printing device, comprising: an arrayed jet printing head and an arrayed plasma module;

The array inkjet printing head comprises a plurality of ink supply nozzles, the upper ends of the ink supply nozzles are connected with an ink supply unit, and the ink flows out of the ink supply unit to fill the ink supply nozzles;

the arrayed plasma module comprises a gas supply unit, a high-voltage power supply and a plurality of plasma units, wherein each plasma unit comprises a plasma generating device and a plasma conveying hose;

the gas supply unit is connected with each plasma generating device through a flowmeter to independently control the conveying of working gas in each plasma unit; the high-voltage power supply is connected with electrode pins in each plasma generating device through an electrical switch so as to independently control each plasma generating device to generate plasma;

One end of the plasma conveying hose is connected with the plasma generating device, and the other end of the plasma conveying hose surrounds the lower end of the ink supply nozzle for a circle to form a plasma gas annular electrode; the plasma gas annular electrode is used for forming an electric field with a grounded substrate to be printed, so that when the electric field intensity of the surface of the ink meniscus breaks through a Taylor limit, the ink is sprayed by a Taylor cone and deposited at a designated position on the substrate to be printed.

2. The plasma-based crosstalk-prevention arrayed electrofluidic inkjet printing apparatus according to claim 1, wherein when the substrate to be printed is a conductive substrate, the conductive substrate is grounded; when the substrate to be printed is an insulating thin substrate, a conductive pad needs to be placed below the insulating thin substrate and grounded.

3. The plasma-based cross-talk prevention arrayed electrofluidic spray printing device of claim 1, wherein the working gas is argon, helium, nitrogen or air.

4. The plasma-based cross-talk prevention arrayed electrofluidic spray printing device of claim 1, wherein the high voltage power source is a pulsed power source or a radio frequency power source.

5. A plasma-based crosstalk-preventing arrayed electrofluidic jet printing method, which is characterized in that the plasma-based crosstalk-preventing arrayed electrofluidic jet printing device is adopted for jet printing.

6. The plasma-based crosstalk-prevention arrayed electrofluidic spray printing method of claim 5, the spray printing method comprising the steps of:

S1, vertically placing an arrayed jet printing head above a substrate to be printed, winding each plasma conveying hose at the lower end of a corresponding ink supply nozzle, and conveying ink to each ink supply nozzle through an ink supply unit, wherein the ink supply nozzle is full of ink, and the ink supply nozzle reaches the outlet of the lower end of the ink supply nozzle;

S2, supplying working gas to a plasma unit to be operated, and switching on a corresponding electrical switch to enable a high-voltage power supply to transmit voltage to an electrode needle of a plasma generating device, wherein the working gas discharges at the electrode needle to generate plasma;

s3, enabling the generated plasma to flow along the plasma conveying hose under the blowing of air flow, forming a plasma gas annular electrode at the lower end of the nozzle in a circle, forming an electric field between the plasma gas annular electrode and the grounded substrate to be printed, and when the electric field intensity of the surface of the meniscus of the ink breaks through the Taylor limit, enabling the ink to be sprayed by the Taylor cone and deposited at a designated position on the substrate to be printed, so that the arrayed electrofluidic jet printing is completed.

7. The plasma-based crosstalk-prevention arrayed electrofluidic inkjet printing method of claim 6, wherein when the flow meter controls the working gas to stop being supplied or the electrical switch controls the electrode needle to be disconnected from the high-voltage power supply, the plasma generation device stops generating plasma, so that the ink supply nozzles stop ejecting ink, and printing is stopped, thereby realizing independent control of each of the ink supply nozzles.